RESUMEN
BACKGROUND: The study of the factors that encourage evidence-based clinical practice, such as structure, environment and professional skills, has contributed to an improvement in quality of care. Nevertheless, most of this research has been carried out in a hospital context, neglecting the area of primary health care. The main aim of this work was to assess the factors that influence an evidence-based clinical practice among nursing professionals in Primary Health Care. METHODS: A multicentre cross-sectional study was designed, taking the 619 Primary Care staff nurses at the Balearic Islands' Primary Health Care Service, as the study population. The methodology applied consisted on a self-administered survey using the instruments Evidence-Based Practice Questionnaire (EBPQ) and Nursing Work Index (NWI). RESULTS: Three hundred and seventy seven surveys were received (60.9% response rate). Self-assessment of skills and knowledge, obtained 66.6% of the maximum score. The Knowledge/Skills factor obtained the best scores among the staff with shorter professional experience. There was a significant difference in the Attitude factor (p = 0.008) in favour of nurses with management functions, as opposed to clinical nurses.Multivariate analysis showed a significant positive relationship between NWI and level of evidence-based practice (p < 0,0001). CONCLUSIONS: Institutions ought to undertake serious reflection on the lack of skills of senior nurses about Evidence-Based Clinical Practice, even when they have more professional experience. Leadership emerge as a key role in the transferral of knowledge into clinical practice.